Complex transcription regulation of acidic chitinase suggests fine-tuning of digestive processes in Drosera binata.

IF 3.6 3区 生物学 Q1 PLANT SCIENCES
Planta Pub Date : 2025-01-12 DOI:10.1007/s00425-025-04607-2
Veronika Mikitova, Martin Jopcik, Miroslav Rajninec, Jana Libantova
{"title":"Complex transcription regulation of acidic chitinase suggests fine-tuning of digestive processes in Drosera binata.","authors":"Veronika Mikitova, Martin Jopcik, Miroslav Rajninec, Jana Libantova","doi":"10.1007/s00425-025-04607-2","DOIUrl":null,"url":null,"abstract":"<p><strong>Main conclusion: </strong>DbChitI-3, Drosera binata's acidic chitinase, peaks at pH 2.5 from 15 °C to 30 °C. Gene expression is stimulated by polysaccharides and suppressed by monosaccharide digestion, implying a feedback loop in its transcriptional regulation. Here, we characterised a novel chitinase gene (DbChitI-3) isolated from the carnivorous plant species Drosera binata with strong homology to other Drosera species' extracellular class I chitinases with a role in digestive processes. The capability to cleave different forms of chitin was tested using recombinantly produced chitinase in Escherichia coli (rDbChitI-3<sup>S-</sup>His) and subsequent purification. The recombinant protein did not cleave chitin powder, the mono-, di- and tri- N-acetyl-D-glucosamine substrates, but cleaved acetic acid-swollen chitin. Fluorometric assay with acetic acid-swollen FITC-chitin as a substrate revealed the maximum enzyme activity at pH 2.5, spanning from 15 °C to 30 °C. Comparing enzymatic parameters with commercial chitinase from Streptomyces griseus showed rDbChitI-3S-His efficiency reaching 64.3% of S. griseus chitinase under optimal conditions. The highest basal expression of DbChitI-3 was detected in leaf blades. In other organs, the expression was either fivefold lower (petioles) or almost nondetectable (stems, roots and flowers). Application of gelatin, chitin, and pachyman resulted in a 3.9-, 4.6- and 5.7-fold increase in the mRNA transcript abundance of DbChitI-3 in leaves. In contrast, monosaccharides and laminarin decreased transcription of the DbChitI-3 gene by at least 70%, 5 h after treatment. The simultaneous application of suppressor and inducer (glucose and pachyman) indicated the predominant effect of the suppressor, implying that sufficient monosaccharide nutrients prioritize absorption processes in D. binata leaves over further digestion of the potential substrate.</p>","PeriodicalId":20177,"journal":{"name":"Planta","volume":"261 2","pages":"32"},"PeriodicalIF":3.6000,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11725546/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Planta","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1007/s00425-025-04607-2","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0

Abstract

Main conclusion: DbChitI-3, Drosera binata's acidic chitinase, peaks at pH 2.5 from 15 °C to 30 °C. Gene expression is stimulated by polysaccharides and suppressed by monosaccharide digestion, implying a feedback loop in its transcriptional regulation. Here, we characterised a novel chitinase gene (DbChitI-3) isolated from the carnivorous plant species Drosera binata with strong homology to other Drosera species' extracellular class I chitinases with a role in digestive processes. The capability to cleave different forms of chitin was tested using recombinantly produced chitinase in Escherichia coli (rDbChitI-3S-His) and subsequent purification. The recombinant protein did not cleave chitin powder, the mono-, di- and tri- N-acetyl-D-glucosamine substrates, but cleaved acetic acid-swollen chitin. Fluorometric assay with acetic acid-swollen FITC-chitin as a substrate revealed the maximum enzyme activity at pH 2.5, spanning from 15 °C to 30 °C. Comparing enzymatic parameters with commercial chitinase from Streptomyces griseus showed rDbChitI-3S-His efficiency reaching 64.3% of S. griseus chitinase under optimal conditions. The highest basal expression of DbChitI-3 was detected in leaf blades. In other organs, the expression was either fivefold lower (petioles) or almost nondetectable (stems, roots and flowers). Application of gelatin, chitin, and pachyman resulted in a 3.9-, 4.6- and 5.7-fold increase in the mRNA transcript abundance of DbChitI-3 in leaves. In contrast, monosaccharides and laminarin decreased transcription of the DbChitI-3 gene by at least 70%, 5 h after treatment. The simultaneous application of suppressor and inducer (glucose and pachyman) indicated the predominant effect of the suppressor, implying that sufficient monosaccharide nutrients prioritize absorption processes in D. binata leaves over further digestion of the potential substrate.

酸性几丁质酶的复杂转录调控表明了果蝇消化过程的微调。
主要结论:Drosera binata的酸性几丁质酶dbchii -3在15°C ~ 30°C pH为2.5时达到峰值。多糖刺激基因表达,单糖消化抑制基因表达,表明其转录调控存在反馈回路。在这里,我们从肉食性植物Drosera binata中分离出一种新的几丁质酶基因(dbchii -3),该基因与其他Drosera物种的细胞外I类几丁质酶具有很强的同源性,并在消化过程中发挥作用。利用重组生产的大肠杆菌几丁质酶(rDbChitI-3S-His)和随后的纯化,测试了其切割不同形式几丁质的能力。重组蛋白不裂解几丁质粉和单、二、三n -乙酰- d-氨基葡萄糖底物,但可裂解醋酸肿胀的几丁质。以醋酸膨胀的fitc -几丁质为底物的荧光测定显示,在pH为2.5时,从15°C到30°C,酶活性最高。与灰链霉菌几丁质酶的酶学参数比较表明,在最优条件下,rDbChitI-3S-His对灰链霉菌几丁质酶的效率可达64.3%。dbchii -3在叶片中表达量最高。在其他器官中,这种表达要么低五倍(叶柄),要么几乎检测不到(茎、根和花)。明胶、几丁质和pachyman分别使叶片中DbChitI-3 mRNA转录物丰度增加3.9倍、4.6倍和5.7倍。相比之下,单糖和层压蛋白在处理后5小时使DbChitI-3基因的转录降低至少70%。同时施用抑制因子和诱导剂(葡萄糖和pachyman)表明,抑制因子的作用占主导地位,这意味着足够的单糖营养物质优先于对潜在底物的进一步消化。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Planta
Planta 生物-植物科学
CiteScore
7.20
自引率
2.30%
发文量
217
审稿时长
2.3 months
期刊介绍: Planta publishes timely and substantial articles on all aspects of plant biology. We welcome original research papers on any plant species. Areas of interest include biochemistry, bioenergy, biotechnology, cell biology, development, ecological and environmental physiology, growth, metabolism, morphogenesis, molecular biology, new methods, physiology, plant-microbe interactions, structural biology, and systems biology.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信